The IBM
PC (known inside IBM as the model 5150) was launched on August 12, 1981
and represented IBM's entry into the microcomputer marketplace.
The IBM PC was almost entirely built out of components made by companies
other than IBM. IBM called this "open architecture" and this
was a great departure from its prior
"personal" computer model, the 5120, built entirely by IBM
in the late 1970s. The IBM PC came bundled with Microsoft's Disk Operating System
(called PC-DOS in its IBM incarnation) and a number of software packages
were ready to go for it on the day of launch, including VisiCorp's
VisiCalc. Don't forget to check out IBM's own special feature on the IBM PC's Debut
including a whole reference section of historic materials.

The IBM
PC changed the personal computing world and its open architecture led
to clones and an entire industry of third party software and hardware
vendors that put this platform on top as the dominant type of microcomputer
by the 1990s. Other vendors fell by the
wayside or ended up surviving in niches as a result. Some commentary
on the open versus closed approaches of IBM and Apple by DigiBarn
curator Bruce Damer may be of interest here. See Erik Klein's movies of the IBM PC booting into PC DOS 1.0 and running cool early applications and get the story of how the IBM PC changed the world in the following interview of Digiban curator Bruce Damer by Marcin Wichary:

Interview of DigiBarn Curator Bruce Damer by Marcin Wichary (of the Guidebook UI Gallery)
on the occaision of the upcoming 25th anniversary of the launch of the IBM PC 5150(Interview from June 2006 for a Polish computing magazine)

MW: What was unique about IBM PC as compared to other machines of its
time?

While the IBM PC was not a particularly advanced machine in terms of architecture and performance, the following made it unique in comparison with other machines of the time that used equivalent or better parts:

The power of the IBM name and marketing clout within the business community, especially in "blue" shops, typically large enterprises where the phrase "nobody ever got fired by going with IBM" held sway.

The "reverse not invented here" syndrome associated with the machine: time pressures and anti-trust concerns forced IBM to put together a machine, service, sales and software that was pretty much from outside the company. To achieve this they had to achieve a working consensus and tight coordination of outside teams pretty much unprecedented in the microcomputer industry. It all came together in Boca Raton, Florida in under a year and in total secrecy, also unprecedented in the early days of the industry.

While dull, the utility and solidity of the case for the CPU and monitor, the heft and ergonomics of the keyboard and the generosity of the expansion slots made the IBM PC 5150 a true piece of office equipment. Sitting next to an IBM PC, an Apple II or any number of other systems looked and felt like a child's toy. This was a very important factor in the business world taking the IBM PC seriously and set the trend for the "beige 80s" when small computers became ubiquitous on desks around the world.

MW: What was the significance of the IBM PC?

Due to its "open architecture" (IBM's own term) the IBM PC created the unique path to the future that the industry needed: a de facto standard controlled by no-one which could be cloned by everyone. More on why this was so important in the next question.

MW: What the world would be like had IBM never launched the IBM PC?

My gosh, the world would be so completely different! Instead of personal computing hardware being a commodity built by a large number of largely anonymous suppliers and able to run a variety of operating systems, a luxury we enjoy today, the world would have been Balkanized into factions of individual companies and groups that build distinct hardware and tied it closely with their own software offerings. This was the situation with the early microcomputer industry but as the IBM PC and its clones caused mass extinction of proprietary software/hardware providers, the entire world adopted one platform. With Apple dropping its own hardware platform in 2005 and becoming another software vendor using an IBM PC clone, that completes the process of the PC being totally triumphant as a standard. Remaining proprietary Unix hardware/software vendors such as Sun Microsystems and SGI have declining market share and poor prospects. Indeed, without the open hardware standard of the IBM PC it is hard to imagine that a vibrant open software movement, or even the widespread adoption of the Internet and Web would have ever occurred. Curator: for a similar view of this, see CNET's Jim Kerstetter Perspective: The great PC 'what-if'.

MW: Did IBM make the mistake of opening up the IBM PC so much?

We should remember that IBM did not set out to make the IBM PC open, it happened by virtue of necessity and in 1987 IBM tried to close the architecture with the introduction of the microchannel PS/2. In retrospect, IBM may have regretted the short term losses brought on by the easy clone-ability of the early IBM PC line but in the long run it gained tremendously. It is hard to imagine IBM having such a large and vibrant Global Services division if it was not for the ubiquitous spread of a common personal computing hardware platform.

NEW: Erik Klein's movies of the original IBM PC booting into PC DOS 1.0 and other applications!

View these superb video captures of an original IBM PC booting up and running PC DOS 1.0 and other applications such as Bill Gates' "donkey.bas". Thank you Erik Klein for taking all the trouble to produce this, and folks please please see and join Erik's Vintage Computer Forums and also see Erik's collection of vintage machines. Now for the movies!